(4R,5S,6S)-3-[[(3S,5S)-5-[[(Aminosulfonyl)amino]methyl]-3-pyrrolidinyl]thio]-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid, commonly known as doripenem of Formula I is a synthetic broad-spectrum carbapenem antibiotic.

Doripenem is available in the market as a monohydrate and it exhibits potent, broad and well-balanced antibacterial activity against a wide range of both Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa. 
U.S. Pat. No. 5,317,016 provides a process for the isolation of doripenem from the reaction mixture by layer separation followed by lyophilization of the aqueous layer. Doripenem is obtained in the above process with a purity of 85%. Similar processes for preparing lyophilized doripenem have also been described in Yasuyoshi Iso, et al., J. Antibiot., 49, pages 199-209 (1996), and Yasuyoshi Iso, et al., J. Antibiot., 49, pages 478-484 (1996). PCT Publication No. WO 2006/117763 provides a process for the isolation of amorphous doripenem from the reaction mixture by layer separation followed by the addition of the aqueous layer to methanol. PCT Publication No. WO 2006/117763 also provides a process for preparing amorphous doripenem by pouring an aqueous solution of doripenem into ethanol. U.S. Pat. Nos. 6,111,098 and 5,703,243 provide processes for preparing crystalline and amorphous lyophilization products of doripenem by lyophilizing the aqueous solutions of doripenem. U.S. Patent Application No. 2003/0153191 provides processes for preparing Type III crystals of doripenem from an aqueous solution of doripenem using Type III seed crystals. According to U.S. Patent Application No. 2003/0153191, the starting aqueous solution is prepared by heating a mixture of water and crude doripenem to 50° to 55° C. and filtering it through activated carbon at a temperature of at least 50° C.
Yutaka Nishino, et al., Org. Process Res. Dev., 7, pages 846-850 (2003), provides a process for the preparation of sterile crystalline doripenem, wherein, crude doripenem is dissolved in water by heating at 55° C., filtered through a funnel pre-coated with activated carbon, a membrane filter (0.2 mm), a membrane for ultra filtration and a filter for the sterilization. The solution is cooled to room temperature, and stirred at 2° C. for 2 hours. Isopropanol is then added and stirred at −5° C. for 4 hours and at −10° C. overnight to obtain sterile doripenem.